# What is L-electron capture?

Jan 8, 2015

Electron capture is said to take place when a proton located in the nucleus of a radioactive element captures an inner-orbital electron, forming a neutron and emitting an electron neutrino.

The process can be described by this nuclear equation

$p + {e}^{-} \to n + {\nu}_{e}$

The electron is usually captured from the K or L electron shells, which correspond to the first and second energy levels.

The K shell corresponds to the principal quantum number n = 1, has 1 subshell, 1s, and can hold 2 electrons. The L shell corresponds to the principal qunatum number n = 2, has 2 subshells, 2s and 2p, and can hold 8 electrons.

Therefore, L-electron capture is said to take place when the captured electron comes from the L shell. Likewise, K-electron capture takes place when the captured electron comes from the K shell.